The Reishi mushroom (Ganoderma lucidum) has a long record of medicinal use in Asia. It grows in fascinating shapes and its shiny, reddish-brown and yellow-banded colouring make it a visually appealing species. Reishi is taken as a health supplement and to treat several illnesses, including HIV/AIDS and cancer. Its action is thought to be primarily immunostimulatory.
Ganoderma lucidum has several common names. The mushroom is called Reishi or Mannentake (10,000 year mushroom) in Japan, and Ling Chi or Ling Zhi (herb of immortality) in China and Korea. Ganoderma is known from Chinese medical writings from over 2,000 years ago and it is a popular symbol and subject in Chinese art. Reishi mushrooms are found worldwide in tropical and subtropical climates. It is a decomposer and grows on dead hardwood. Several similar species are found in North America, and it is possible that these are ecotypes or variants of Ganoderma lucidum and not truly distinct species. Reishi mushrooms are easily grown on logs or in bags of sawdust/wood chips using techniques similar to those used for other wood-inhabiting mushrooms. Commercial cultivation is well established in Asia and to some degree in North America.
Like all mushrooms, Reishi is a good source of B vitamins and amino acids. Polysaccharides are suspected to be a major active ingredient in many mushrooms consumed for medicinal use. Reishi extracts contain elevated quantities beta-glucan polysaccharides as well as triterpenoids (ganodermic acids). For general health benefits, Reishi is taken as a general immune system stimulant, to boost energy and to combat fatigue. Research has shown that Reishi extracts have interesting and potentially useful medicinal activity. The results of in vitro, animal and some human studies indicate the following beneficial affects: • Stimulation of macrophages (immune cells) and interleukins (anti-tumour) • Inhibition of platelet aggregation (anti-blood clotting) • Nausea reduction after chemotherapy • Antioxidant activity • Immunostimulation in cancer and HIV patients • Cholesterol lowering • Anti-inflammatory Confirmation of clear and repeatable benefits in human studies is lacking. Improved outcomes in cancer patients who use Reishi in addition to a traditional course of treatment have been reported but the contribution of Reishi in these cases is not well understood. In the absence of a demonstrated adverse affect, or excessively high dose, taking Reishi concurrently with another course of treatment is unlikely to do harm.
Most people tolerate Reishi well. The first use should be a small dose of tea or extract to make sure there is no allergic reaction. Possible minor side effects include: • Nausea • Vomiting • Diarrhea • Stomach discomfort • Dry nose and throat Very high doses may be damaging to cells but this has not been shown in actual use. Interference with the effectiveness of some drugs (especially immunosuppressants) is possible but not well substantiated.
Reishi is made into a tea by boiling broken up mushroom pieces until they become soft. The pieces are then steeped for an additional half-hour, and consumed after straining out the solids. The tea can be made in batches and refrigerated for later use. The taste varies from a mildly sweet and rich flavour to bitter, depending on the particular mushroom strain. Two to three grams of liquid tea per day is recommended if taken as a health supplement. For medicinal use, a more controlled and concentrated dose is suggested, in the form of Reishi extract.
Crushed and powdered Reishi mushrooms are not usually consumed directly because their hard and tough cells are difficult to digest. Reishi can be administered as an extract, usually in capsule form. To make the extract, the mushrooms are cooked at high temperature in either water or alcohol. After centrifuging to remove solids, the remaining liquid is vacuum dried to form the final product. The extract is taken in 200-1000mg doses.